CVE-2026-67399

EUVD-2026-78136
Deserialization of untrusted data in WHMCS 9.0.0 before 9.0.8 and 8.0.0 before 8.13.7 allows remote attackers to execute arbitrary code.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.3 CRITICAL
NETWORK
LOW
NONE
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 54.93%
Common Weakness Enumeration
References
https://help.whmcs.com/m/125386/l/2118034-cve-2026-67399-whmcs-security-update-2026-09-03